Electronystagmographic study in rabbits on the vestibular effect of vincamine

Vincamine (Vincapront), the alcaloid isolated from Vinca minor L, was tested in rabbits at three dosages (1 mg/kg, 5 mg/kg, 10 mg/kg i.m.) in an electronystagmographic study. The parameters evaluated were: duration, rate and frequency of the post-rotatory nystagmus and the frequency of the per-rotatory nystagmus. While the post-rotatory nystagmus was found to show a reduction in duration and rate, the frequencies did not respond to vincamine. The 1 mg/kg dose had the strongest effect while that of the 10 mg/kg dose was weakest. As these findings may not be explained by sedative or habituation effects we consider the reduction of the post-rotatory nystagmus as an analogue in animal experiments of the vestibular effect seen in man. The electronystagmographic pattern of action corresponds to that of some other antivertiginous drugs.